System and methods for imaging employing a levitating conveyor

ABSTRACT

A system and methodology for conveying generally planar substrates such as printed circuit board, flat panel display and interconnect device substrates, in a levitated state, to and from a scanning or imaging location, including an air flow conveyor having a substrate flattening functionality, and a scanning or imaging device, and scanning and imaging systems and methodologies employing such article conveying systems and methodologies.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication No. 60/342,374, filed Dec. 27, 2001, the disclosure of whichis incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to article transport and conveying systemsand methodologies generally, and more particularly to imaging systemsand methodologies employing such transport and conveying systems.

BACKGROUND OF THE INVENTION

Systems and methodologies for transporting and conveying articles thatare suitable for use in imaging systems, such as laser direct writesystems and inspection systems, are characterized, inter alia, by highlyprecise and highly repeatable rates of transport. Moreover such systemsand methodologies are configured to maintain articles in a precisepredetermined orientation, including a precise distance, relative to animager and are configured to minimize mechanical disturbance to anarticle being transported at the imager by other articles that are beinguploaded to or offloaded from the system.

SUMMARY OF THE INVENTION

A general aspect of the present invention relates to improved articletransport and conveying systems and methodologies employing an articlelevitator levitating an article during transporting and conveying. Aflattener is provided to ensure that a levitated portion of the articleis precisely held in a desired orientation relative to a processorduring processing. Preferably the flattener operates in a non-contactmanner.

Such transport and conveying systems may be employed for transportingand conveying generally planar substrates, particularly wherever thereis required one or more of the following: a relatively high degree ofuniformity in the rate of transport, a high degree of precision in theorientation of the substrate in relation to a processor (for example animage acquisition system or an image creator), or avoidance ofdisturbance to a substrate during process, for example due to theloading or unloading of other substrates onto or off of the transportand conveying system. Typical applications of such systems includeinspection and testing, such as automated optical inspection, electricaltesting and functional testing, of flat panel displays and electricalcircuits such as printed circuit boards and semiconductor wafers, andimage formation on a photosensitized surface such as in-fabrication flatpanel displays, electrical circuits, reticules and photo tools. Othertypical applications included systems for conveying planar sheetmaterial such as metal foils, planar plastic laminates and any othersuitable sheet material.

There is thus provided in accordance with a preferred embodiment of thepresent invention an imaging system for use with generally planarsubstrates including an air flow conveyor operative to convey planarsubstrates at least to an imaging location, the air flow conveyor havingan air flow substrate flattening functionality at least at the imaginglocation; and an imager located at the imaging location for imaging theplanar substrates when flattened by the air flow substrate flatteningfunctionality.

Additionally, the air flow conveyor may be operative to convey theplanar substrates away from the imaging location.

Preferably, the imager includes an image acquirer, such as an automatedoptical inspection device electrical testing, metrology or any othersuitable image acquisition device. Alternatively or additionally, theimager may include an image creator such as a modulated laser scanner.

The air flow conveyor preferably includes an air flow levitator.Alternatively or additionally, the air flow conveyor may include an airflow hold down. Alternatively or additionally, the air flow conveyor mayinclude a displacer for displacing the planar substrates towards theimaging location or away from the imaging location or both.

The air flow substrate flattening functionality, preferably, includes avacuum hold down. Alternatively or additionally, the air flow flatteningfunctionality includes an air flow evacuator or outlet operative torelease air build up beneath the planar substrate. Alternatively oradditionally, the air flow substrate flattening functionality includesan air flow hold down. Preferably, the vacuum hold down, or the air flowhold down, are operative in combination with the air flow levitator tohold the substrate a precise distance from a reference surface.

There is also provided in accordance with a preferred embodiment of thepresent invention a two-sided imaging system for use with generallyplanar substrates including an air flow conveyor operative to conveyplanar substrates in a levitated state at least to an imaging location;and an imager located at the imaging location for imaging two oppositesides of the planar substrates when levitated by the air flow conveyor.

Additionally, the air flow conveyor may be operative to convey theplanar substrates away from the imaging location.

Preferably, the imager includes an image acquirer, such as automaticoptical inspection device. Alternatively or additionally, the imager mayinclude an image creator. Optionally the imager provides illuminationfrom a first side of a planar substrate and acquires an image from theopposite side of the substrate.

Preferably, the air flow conveyor includes air flow substrate flatteningfunctionality at least at the imaging location.

The air flow conveyor, preferably, includes an air flow hold down or avacuum hold down. Alternatively or additionally, the air flow conveyormay include a displacer for displacing the planar substrates towards theimaging location or away from the imaging location or both.

The air flow substrate flattening functionality preferably includes avacuum hold down. Alternatively or additionally, the air flow flatteningfunctionality includes an air flow evacuator. Alternatively oradditionally, the air flow substrate flattening functionality includesan air flow hold down. Preferably, the vacuum hold down, or the air flowhold down, are operative in combination with the air flow levitator tohold the substrate a precise distance from a reference surface.

There is also provided in accordance with a preferred embodiment of thepresent invention an air flow conveyor system including: an air flowgenerator; and an air flow levitating conveyor operative to conveyplanar substrates. Preferably, the air flow conveyor includes: adisplacer for displacing the planar substrates; and an air flowsubstrate flattener operative at least at one region of the levitatingconveyor to flatten the planar substrate when in a levitated state.

The air flow conveyor, preferably, includes an air flow hold down.

The air flow substrate flattening functionality, preferably, includes avacuum hold down. Alternatively or additionally, the air flow flatteningfunctionality includes an air flow evacuator. Alternatively oradditionally, the air flow substrate flattening functionality includesan air flow hold down. Preferably, the vacuum hold down, or the air flowhold down, are operative in combination with the air flow levitator tohold the substrate a precise distance from a reference surface.

There is also provided in accordance with a preferred embodiment of thepresent invention a flat bed scanner system including: an air flowconveyor operative to convey planar substrates to be scanned at least toa scanning location, the air flow conveyor having an air flow substrateflattening functionality at least at the scanning location; and ascanner located at the scanning location for scanning the planarsubstrates when flattened by the air flow substrate flatteningfunctionality.

Additionally, the air flow conveyor may be operative to convey theplanar substrates away from the imaging location.

Preferably, the scanner includes, in part, an image acquirer.Alternatively or additionally, the scanner may include, in part, animage creator. Optionally, the scanner is a laser scanner employing arotating polygon.

Preferably, the planar substrates include a photosensitive layer, wherethe image creator includes a data modulated laser beam device operativeto expose a desired pattern on the photosensitive layer.

The air flow conveyor, preferably, includes an air flow levitator.Alternatively or additionally, the air flow conveyor includes an airflow hold down or a vacuum hold down. Alternatively or additionally, theair flow conveyor may include a displacer for displacing the planarsubstrates towards the imaging location or away from the imaginglocation or both.

The air flow substrate flattening functionality preferably includes avacuum hold down. Alternatively or additionally, the air flow flatteningfunctionality includes an air flow evacuator. Alternatively oradditionally, the air flow substrate flattening functionality includesan air flow hold down. Preferably, the vacuum hold down, or the air flowhold down, are operative in combination with the air flow levitator tohold the substrate a precise distance from a reference surface.

There is also provided in accordance with a preferred embodiment of thepresent invention a levitated conveyor system including: a levitatoroperative to levitate planar substrates with respect to a surface; and adisplacer for displacing the planar substrates generally parallel to thesurface; The conveyor system additionally includes a substrate flatteneroperative to flatten the planar substrate when in a levitated state.

Preferably, the levitator includes an air flow levitator.

Preferably, the substrate flattener includes a positive pressure device.Alternatively or additionally, the substrate flattener includes a vacuumor suction pressure device forming a region of sub-atmospheric pressure.Preferably, the flattener is operative in combination with the levitatorto hold the substrate a precise distance from the surface.

There is also provided in accordance with a preferred embodiment of thepresent invention a methodology for imaging generally planar substratesincluding: conveying the planar substrates, employing an air flowconveyor, to at least an imaging location, the air flow conveyor havingan air flow substrate flattening functionality at least at the imaginglocation; and imaging the generally planar substrates, employing animager located at the imaging location, when the generally planarsubstrates are flattened by the air flow substrate flatteningfunctionality.

The conveying may also include conveying the planar substrates away fromthe imaging location.

The imaging preferably includes image acquisition. Alternatively oradditionally, the imaging includes image creation. Optionally, imagingincludes illuminating a substrate from a first side and acquiring animage from the opposite side thereof.

The air flow conveyor preferably includes an air flow levitator.Alternatively or additionally, the air flow conveyor includes an airflow hold down. The air flow conveyor also, preferably, includes adisplacer for displacing the planar substrates towards the imaginglocation or away from the imaging location or both.

Preferably, the air flow substrate flattening functionality includes ana vacuum hold down. Alternatively or additionally, the air flowflattening functionality includes an air flow evacuator. Alternativelyor additionally, the air flow substrate flattening functionalityincludes an air flow hold down. Preferably, the vacuum hold down, or theair flow hold down, are operative in combination with the air flowlevitator to hold the substrate a precise distance from a referencesurface.

There is also provided in accordance with a preferred embodiment of thepresent invention a methodology for two-sided imaging of generallyplanar substrates including: conveying the planar substrates in alevitated state, employing an air flow conveyor, to at least an imaginglocation; and imaging two opposite sides of the planar substrates whenlevitated by the air flow conveyor, employing an imager located at theimaging location.

The conveying may also include conveying the planar substrates away fromthe imaging location.

The imaging preferably includes image acquisition. Alternatively oradditionally, the imaging includes image creation. Optionally, imagingincludes illuminating a substrate from a first side and acquiring animage from the opposite side thereof.

Preferably, the air flow conveyor includes air flow substrate flatteningfunctionality at least at the imaging location. Alternatively oradditionally, the air flow flattening functionality includes an air flowevacuator. Alternatively or additionally, the air flow conveyor includesan air flow hold down. Preferably, the vacuum hold down, or the air flowhold down, are operative in combination with the air flow levitator tohold the substrate a precise distance from a reference surface. The airflow conveyor also, preferably, includes a displacer for displacing theplanar substrates towards the imaging location or away from the imaginglocation or both.

Preferably, the air flow substrate flattening functionality includesvacuum hold down. Alternatively or additionally, the air flow substrateflattening functionality includes an air flow hold down.

There is also provided in accordance with a preferred embodiment of thepresent invention an air flow conveying methodology including:generating an air cushion beneath a generally planar substrate using anair flow generator; and conveying planar substrates using an air flowlevitating conveyor. The conveying includes: displacing the planarsubstrates using a displacer; and flattening the planar substrates whenin a levitated state, the flattening employing an air flow substrateflattener at least at one region of the levitating conveyor. Theflattening positions at least a portion of the substrate in a givenplane of reference in a levitated state.

Preferably, the air flow conveyor includes an air flow hold down.Preferably, the air flow substrate flattening functionality includesvacuum hold down. Alternatively or additionally, the air flow flatteningfunctionality includes an air flow evacuator or outlet operative torelease air build up beneath the planar substrate. Alternatively oradditionally, the air flow substrate flattening functionality includesan air flow hold down. Preferably, the vacuum hold down, or the air flowhold down, are operative in combination with the air flow levitator tohold the substrate a precise distance from a reference surface.

There is also provided in accordance with a preferred embodiment of thepresent invention a methodology for scanning generally planar substratesincluding: conveying planar substrates to be scanned, employing an airflow conveyor, to at least a scanning location, the air flow conveyorhaving an air flow substrate flattening functionality at least at thescanning location; and scanning the planar substrates, employing ascanner located at the scanning location, when flattened by the air flowsubstrate flattening functionality.

The conveying may also include conveying the planar substrates away fromthe imaging location.

The scanning preferably includes, in part, image acquisition.Alternatively or additionally, the scanning includes, in part, imagecreation.

Preferably, the planar substrates include a photosensitive layer.Preferably, the image creation includes exposing a desired pattern onthe photosensitive layer, employing a modulated laser beam device.

The air flow conveyor preferably includes an air flow levitator.Alternatively or additionally, the air flow conveyor includes an airflow hold down or a vacuum hold down. Alternatively or additionally, theair flow flattening functionality includes an air flow evacuator.Preferably, the vacuum hold down, or the air flow hold down, areoperative in combination with the air flow levitator to hold thesubstrate a precise distance from a reference surface.

The air flow conveyor also, preferably, includes a displacer fordisplacing the planar substrates towards the imaging location or awayfrom the imaging location or both.

Preferably, the air flow substrate flattening functionality includes anair flow levitator. Alternatively or additionally, the air flowsubstrate flattening functionality includes an air flow hold down.

There is also provided in accordance with a preferred embodiment of thepresent invention a levitating methodology for conveying generallyplanar substrates including: levitating planar substrates with respectto a surface, employing a levitator; displacing the planar substratesgenerally parallel to the surface employing a displacer; and flatteningthe planar substrates when in a levitated state, employing a substrateflattener.

In an embodiment of the invention the levitating includes vacuumlevitation.

Preferably, the substrate flattener includes a positive pressure device.Alternatively or additionally, the substrate flattener includes a avacuum or suction device forming a region of sub-atmospheric pressure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated more fully fromthe following detailed description, taken in conjunction with thedrawings in which:

FIG. 1A is a simplified illustration of a portion of a levitatedconveyor system constructed and operative in accordance with a preferredembodiment of the present invention;

FIG. 1B is a simplified illustration of a portion of a levitatedconveyor system constructed and operative in accordance with anotherpreferred embodiment of the present invention;

FIG. 2A is a simplified illustration of a levitated conveyor systemconstructed and operative in accordance with a preferred embodiment ofthe present invention;

FIG. 2B is a simplified illustration of a levitated conveyor systemconstructed and operative in accordance with another preferredembodiment of the present invention;

FIG. 3A is a simplified illustration of a portion of a levitatedinspection system constructed and operative in accordance with apreferred embodiment of the present invention;

FIG. 3B is a simplified illustration of a portion of a levitatedinspection system constructed and operative in accordance with anotherpreferred embodiment of the present invention;

FIG. 4A is a simplified illustration of a portion of a levitated imagingsystem constructed and operative in accordance with a preferredembodiment of the present invention;

FIG. 4B is a simplified illustration of a portion of a levitated imagingsystem constructed and operative in accordance with another preferredembodiment of the present invention;

FIG. 5A is a simplified illustration of a portion of a levitatedtwo-sided imaging system constructed and operative in accordance with apreferred embodiment of the present invention;

FIG. 5B is a simplified illustration of a portion of a levitatedtwo-sided imaging system constructed and operative in accordance withanother preferred embodiment of the present invention; and

FIG. 6 is a simplified illustration of an electrical circuit inspectionsystem constructed and operative in accordance with a preferredembodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Reference is now made to FIG. 1A, which is a simplified illustration ofa portion of a levitated conveyor system constructed and operative inaccordance with a preferred embodiment of the present invention. As seenin FIG. 1A, a generally planar substrate 100 is levitated by a pressurecushion, for example by a flow of fluid, preferably air, from amultiplicity of nozzles 102 connected via a manifold 104 to a source ofpositive fluid pressure 106.

As used herein the term “flow of fluid” or “air flow” refers to theformation of a region of pressure, greater than atmospheric pressure, atleast in the vicinity of a substrate. The formation of such a region ofpressure may be done for example by generating an active flow of fluid.Alternatively the formation of such a region of pressure may be donewithout generating an active flow of fluid, or by generating aninsignificant active flow of fluid, for example using apparatus andmethods described in published PCT Patent Application WO 01/14782 A1,published PCT Patent Application WO 01/14752 A1 and published PCT PatentApplication WO 01/19572 A1. As used herein, the term generally “planarsubstrate” refers to any suitable generally planar sheet material suchas, for example, paper, cardboard, metallic sheet, glass, fiberglasssheets, celluloid, sheet film, silicon wafers and the like. Uses of suchmaterials include planar substrates bearing pixel arrays employed inflat panel displays, mask works employed in electrical circuitproduction, printed circuit board substrates bearing portions of anelectrical circuit pattern, semiconductor chips and interconnect devicesinterconnecting between semiconductor chips and printed circuit boards.Generally planar substrates include planar sheet materials which alreadyhave formed thereupon portions of a flat panel display or of anelectrical circuit, as well as planar sheet materials which are suitableto have formed thereupon flat panel display portions or electricalcircuit patterns. The generally planar surface may have aphotosensitized surface, for example a photoresist material depositedthereon.

It is appreciated that when a generally planar substrate 100 islevitated as seen in FIG. 1A, normally the planar substrate 100 would bebowed, or otherwise not uniformly flat, as shown in dashed lines atreference numeral 108. In order to flatten the planar substrate 100, atleast over a given portion thereof, there is provided, in accordancewith a preferred embodiment of the present invention, a suction such asa counter flow of fluid, preferably air, preferably from a multiplicityof nozzles 112 connected via a manifold 114 to the source of positivefluid pressure 106. In the embodiment of FIG. 1A, nozzles 112 andmanifold 114 are located on an opposite side of the planar substrate 100from where a pressure cushion provided by nozzles 102 is formed.

Reference is now made to FIG. 1B, which is a simplified illustration ofa portion of a levitated conveyor system constructed and operative inaccordance with another embodiment of the present invention. As seen inFIG. 1B, a generally planar substrate 150 is levitated by a pressurecushion, for example a flow of fluid, preferably air, from amultiplicity of nozzles 152 connected via a manifold 154 to a source ofpositive fluid pressure 156.

It is appreciated that in such a case, normally the planar substrate 150would be bowed, or otherwise not uniformly flat, as shown in dashedlines at reference numeral 158. In order to flatten the planar substrate150, at least over a given portion thereof, there is provided, inaccordance with a preferred embodiment of the present invention, suctionfrom a multiplicity of nozzles 162 connected via a manifold 164 to asource of suction 166. In the embodiment of FIG. 1B, nozzles 162 andmanifold 164 are located on the same side of the planar substrate 150 asthat where a pressure cushion is provided by nozzles 152. An example ofa particular embodiment of levitated conveyor system for conveying aplanar substrate and employing a levitating flow of a fluid inconjunction with a suction is generally described in PCT patentapplication ______ to Core Flow Ltd., entitled High PerformanceNon-Contact Support Platforms (Attorney Docket 1203/20), and filed onDec. 27, 2002, the disclosure of which is incorporated by reference inits entirety.

It is appreciated that alternatively any other suitable type oflevitation may be employed, such as, for example, magnetic levitation,in conjunction with a suitable article.

Reference is now made to FIG. 2A, which is a simplified illustration ofa levitated conveyor system constructed and operative in accordance witha preferred embodiment of the present invention. As seen in FIG. 2A, thelevitated conveyor system preferably includes a static levitation table200 including a multiplicity of apertures 202. A generally planarsubstrate 204 is levitated by a pressure cushion, for example providedby a flow of fluid, preferably air, from a multiplicity of nozzles 206,preferably in communication with corresponding apertures 202, in amanifold 208 that is connected to a source of positive fluid pressure210.

It is appreciated that absent the presence of a counter-flow of fluid,or other suitable hold down force, the levitated planar substrate may bebowed, or otherwise not uniformly flat, as shown at reference numerals212 and 214. As shown in FIG. 2A, at a location 216 along the levitationtable 200, where it is desired that the planar substrate be flattened,there is provided, in accordance with a preferred embodiment of thepresent invention, a counter flow of fluid, preferably air, forming acounter pressure cushion, preferably from a multiplicity of nozzles 222connected via a manifold 224 to the source of positive fluid pressure210. In the embodiment of FIG. 2A, nozzles 222 and manifold 224 arelocated on an opposite side of the planar substrate 204 from that wherea pressure cushion is provided by nozzles 206.

The levitated conveyor system of FIG. 2A preferably also includes atleast one displacer 226 for moving the levitated planar substrate alongand preferably parallel to table 200. The displacer 226 preferablycomprises a track 228 disposed parallel to the table 200. A carriageassembly 230 is driven along track 228 and preferably includes grippers232 which engage the planar substrate 204 and cause it to be displacedparallel to track 228. It is appreciated that alternatively, any othersuitable type of contact or non-contact displacer, such as a pusher orpuller, may be employed. It is noted that when levitated, for example byan pressure cushion, substrate 204 can be readily laterally displaced,that displacer 226 does not need to support the full weight of substrate204 and that displacer 226 only needs to provide a displacingfunctionality.

Reference is now made to FIG. 2B, which is a simplified illustration ofa levitated conveyor system constructed and operative in accordance witha preferred embodiment of the present invention. As seen in FIG. 2B, thelevitated conveyor system preferably includes a static levitation table250 including a multiplicity of apertures 252. A generally planarsubstrate 254 is levitated by a flow of fluid, preferably air, from amultiplicity of nozzles 256, preferably in communication withcorresponding apertures 252, in a manifold 258 that is connected to asource of positive fluid pressure 260.

It is appreciated that absent the presence of a counter-flow of fluid,or other suitable hold down force, the levitated planar substrate may bebowed, or otherwise not uniformly flat, as shown at reference numerals262 and 264. As shown in FIG. 2B, at a location 266 along the levitationtable 250, where it is desired that the planar substrate be flattened,there is provided, in accordance with an embodiment of the presentinvention, a counter flow of fluid. The counter flow may be simply afluid evacuator providing an outlet for evacuating air accumulatingbetween planar substrate 254 and static levitation table 250. Preferablycounter flow is a vacuum flow or suction operative to hold at least aportion of planar substrate 254 in a plane that is located a precisedistance from the surface of table 200. The counter flow preferably isprovided by a multiplicity of nozzles 272 connected via a manifold 274to a source of suction 276. In the embodiment of FIG. 2B, nozzles 272and manifold 274 are located on the same side of the planar substrate254 as that where a pressure cushion provided by nozzles 256 incommunication with suitable apertures 252 is formed.

The levitated conveyor system of FIG. 2B preferably also includes adisplacer 276 for moving the levitated planar substrate, along andpreferably parallel to table 250. The displacer 276 preferably comprisesa track 278 disposed parallel to the table 250. A carriage assembly 280is driven along track 278 and preferably includes grippers 282 whichengage the planar substrate 254 and cause it to be displaced parallel totrack 278. It is appreciated that alternatively, any other suitable typeof contact or non-contact displacer, such as a pusher or puller, may beemployed.

It is a particular feature of the embodiment of FIG. 2B that at leastsome of the nozzles 256 and 272 are coupled to an adaptive orificedevice which limits the fluid flow therethrough in the absence of alevitated planar surface in operative engagement therewith. The adaptiveorifice devices may be conveniently located in communication withapertures 252 in table 250. Preferred embodiments of adaptive orificedevices operative to provide a pressure cushion, or suction, withreduced flow of air are described in the following references, thedisclosures of which are hereby incorporated by reference in theirentirety:

-   -   Published PCT Patent Application WO 01/14782 A1    -   Published PCT Patent Application WO 01/14752 A1    -   Published PCT Patent Application WO 01/19572 A1.

It is appreciated that any other suitable adaptive or non-adaptiveorifice devices may be used.

Reference is now made to FIG. 3A, which is a simplified illustration ofa portion of a levitated inspection system constructed and operative inaccordance with a preferred embodiment of the present invention. As seenin FIG. 3A, the levitated inspection system preferably includes a staticlevitation table 300 including a multiplicity of apertures 302. Agenerally planar substrate 304 is levitated by a pressure cushion, forexample provided by a flow of fluid, preferably air, from a multiplicityof nozzles 306, preferably in communication with corresponding apertures302, that are connected via a manifold 308 to a source of positive fluidpressure 310.

It is appreciated that absent the presence of a counter-flow of fluid,or other suitable hold down force, the levitated planar substrate 304may be bowed, or otherwise not uniformly flat, as shown at referencenumerals 312 and 314. As shown in FIG. 3A, at an inspection location 316along the levitation table 300, at which an inspection device 318, suchas a laser scanner or other suitable, for example generally white light,optical imager, is operative, it is desired that the planar substrate304 be flattened or otherwise maintained in a precise given orientationrelative to inspection device 318. Accordingly, there is provided, in apreferred embodiment of the present invention, a counter flow of fluid,preferably air, forming a counter pressure cushion, preferably from amultiplicity of nozzles 322 connected via a manifold 324 to the sourceof positive fluid pressure 310. In the embodiment of FIG. 3A, nozzles322 and manifold 324 are located on an opposite side of the planarsubstrate 304 from that where a pressure cushion is provided by nozzles306.

The levitated inspection system of FIG. 3A preferably also includes atleast one displacer 326 for moving the levitated planar substrate, alongand preferably parallel to table 300. The displacer 326 preferablycomprises a track 328 disposed parallel to the table 300. A carriageassembly 330 is driven along track 328 and preferably includes grippers332 which engage the planar substrate 304 and cause it to be displacedparallel to track 328. It is appreciated that alternatively, any othersuitable type of contact or non-contact displacer, such as a pusher orpuller, may be employed. It is noted that when levitated, for example byan pressure cushion, substrate 304 can be readily laterally displaced,that displacer 326 does not need to support the full weight of substrate304 and that displacer 326 only needs to provide a displacingfunctionality.

Reference is now made to FIG. 3B, which is a simplified illustration ofa levitated inspection system constructed and operative in accordancewith a preferred embodiment of the present invention. As seen in FIG.3B, the levitated conveyor system preferably includes a staticlevitation table 350 including a multiplicity of apertures 352. Agenerally planar substrate 354 is levitated by a flow of fluid,preferably air, from a multiplicity of nozzles 356, preferablycommunicating with corresponding apertures 352, which are connected viaa manifold 358 to a source of positive fluid pressure 360.

It is appreciated that absent the presence of a counter-flow of fluid,or other suitable hold down force, the levitated planar substrate may bebowed or otherwise not uniformly flat, as shown at reference numerals362 and 364. As shown in FIG. 3B, at an inspection location 366 alongthe levitation table 350, at which an inspection device 368, such as alaser scanner or other suitable scanner, for example a generally whitelight optical imager, is operative, it is desired that the planarsubstrate be flattened or otherwise maintained in a given orientationrelative to, for example a precise distance from, inspection device 368.

Accordingly, there is provided, in a preferred embodiment of the presentinvention, a counter flow of fluid. The counter flow may be simplyprovided by a fluid evacuator providing an outlet for evacuating airaccumulating between planar substrate 354 and static levitation table350. Preferably the counter flow of fluid is a vacuum flow or suctionoperative to hold at least a portion of planar substrate 354 in a planethat is located a precise distance from the surface of table 300, or anyother suitable reference surface. The counter flow preferably isprovided by a multiplicity of nozzles 372 connected via a manifold 374to a source of suction 376. In the embodiment of FIG. 3B, nozzles 372and manifold 374 are located on the same side of the planar substrate354 as that where a pressure cushion provided by nozzles 356 incommunication with suitable apertures 352 is formed.

The levitated conveyor system of FIG. 3B preferably also includes adisplacer 376 for moving the levitated planar substrate, along andpreferably parallel to table 350. The displacer 376 preferably comprisesa track 378 disposed parallel to the table 350. A carriage assembly 380is driven along track 378 and preferably includes grippers 382 whichengage the planar substrate 354 and cause it to be displaced parallel totrack 378. It is appreciated that alternatively, any other suitable typeof contact or non-contact displacer, such as a pusher or puller, may beemployed.

It is a particular feature of the embodiment of FIG. 3B that at leastsome of the nozzles 356 and 372 are coupled to an adaptive orificedevice which limits the fluid flow therethrough in the absence of alevitated planar surface in operative engagement therewith. The adaptiveorifice devices may be conveniently located in communication withapertures 352 in table 350. Preferred embodiments of adaptive orificedevices operative to provide a pressure cushion, or suction, withreduced flow of air are described in the following references, thedisclosures of which are hereby incorporated by reference in theirentirety:

-   -   Published PCT Patent Application WO 01/14782 A1    -   Published PCT Patent Application WO 01/14752 A1    -   Published PCT Patent Application WO 01/19572 A1.

It is appreciated that any other suitable adaptive or non-adaptiveorifice devices may be used.

Reference is now made to FIG. 4A, which is a simplified illustration ofa portion of a levitated imaging system constructed and operative inaccordance with a preferred embodiment of the present invention. Theimaging system of FIG. 4A may be an image acquisition system or an imagewriting system or both. In the illustrated embodiment, an image writingsystem is shown, it being understood that the structure described isapplicable also to an image acquisition system or to a combined imageacquisition and writing system and corresponding methodologies.

As seen in FIG. 4A, the levitated imaging system preferably includes astatic levitation table 400 including a multiplicity of apertures 402. Agenerally planar substrate 404 is levitated by a pressure cushion, forexample provided by a flow of fluid, preferably air, from a multiplicityof nozzles 406, preferably in communication with corresponding apertures402, that are connected via a manifold 408 to a source of positive fluidpressure 410.

It is appreciated that absent the presence of a counter-flow of fluid,or other suitable hold down force, the levitated planar substrate 404may be bowed, or otherwise not uniformly flat, as shown at referencenumerals 412 and 414. As shown in FIG. 4A, at an imaging location 416along the levitation table 400, there is provided an imaging device 418,such as a flat bed plotter functioning as a direct imager forming apattern on the surface of planar substrate 404, preferably inassociation with a planar substrate having a photosensitive layer.Imaging device 418 is optionally a laser scanner employing a rotatingpolygon (not shown) to scan a data modulated laser beam across thesurface of planar substrate 404.

At the imaging location 416, it is desired that the planar substrate beflattened or otherwise maintained in a given orientation relative toimaging device 418 during imaging. Accordingly, there is provided, in apreferred embodiment of the present invention, a counter flow of fluid,preferably air, forming a counter pressure cushion, preferably from amultiplicity of nozzles 422 connected via a manifold 424 to the sourceof positive fluid pressure 410. In the embodiment of FIG. 4A, nozzles422 and manifold 424 are located on an opposite side of the planarsubstrate 404 from that where a pressure cushion is provided by nozzles406.

The levitated imaging system of FIG. 4A preferably also includes atleast one displacer 426 for moving the levitated planar substrate, alongand preferably parallel to table 400. The displacer 426 preferablycomprises a track 428 disposed parallel to the table 400. A carriageassembly 430 is driven along track 428 and preferably includes grippers432 which engage the planar substrate 404 and cause it to be displacedparallel to track 428. It is appreciated that alternatively, any othersuitable type of contact or non-contact displacer, such as a pusher orpuller, may be employed. It is noted that when levitated, for example byan pressure cushion, substrate 404 can be readily laterally displaced,that displacer 426 does not need to support the full weight of substrate404 and that displacer 426 only needs to provide a displacingfunctionality.

Reference is now made to FIG. 4B, which is a simplified illustration ofa portion of a levitated imaging system constructed and operative inaccordance with a preferred embodiment of the present invention. Theimaging system of FIG. 4B may be an image acquisition system or an imagewriting system or both. In the illustrated embodiment, an image writingsystem is shown, it being understood that the structure described isapplicable also to an image acquisition system or to a combined imageacquisition and writing system and corresponding methodologies, or toany other processing requiring a portion of a substrate to be located avery precise distance from a processing station.

As seen in FIG. 4B, the levitated imaging system preferably includes astatic levitation table 450 including a multiplicity of apertures 452. Agenerally planar substrate 454 is levitated by a pressure cushion, forexample provided by a flow of fluid, preferably air, from a multiplicityof nozzles 456, preferably in communication with corresponding apertures452, that are connected via a manifold 458 to a source of positive fluidpressure 460.

It is appreciated that absent the presence of a counter-flow of fluid,or other suitable hold down force, the levitated planar substrate may bebowed, or otherwise not uniformly flat, as shown in at referencenumerals 462 and 464. As shown in FIG. 4B, at an imaging location 466along the levitation table 450, there is provided an imaging device 468,such as a flat bed plotter functioning as a direct imager forming apattern on the surface of planar substrate 454, preferably inassociation with a planar substrate having a photosensitive layer.Imaging device 468 is optionally a laser scanner employing a rotatingpolygon (not shown) to scan a data modulated laser beam across thesurface of planar substrate 404.

At the imaging location 466, it is desired that the planar substrate beflattened or otherwise maintained in a given orientation relative to,for example a precise distance from, imaging device 418 during imaging.Accordingly, there is provided, in a preferred embodiment of the presentinvention, a counter flow of fluid. The counter flow may be simply afluid evacuator providing an outlet for evacuating air accumulatingbetween planar substrate 454 and static levitation table 450. Preferablycounter flow is a vacuum flow operative to hold at least a portion ofplanar substrate 450 in a plane that is located a precise distance fromthe surface of table 400. The counter flow preferably is provided bymultiplicity of nozzles 472 connected via a manifold 474 to a source ofsuction 476. In the embodiment of FIG. 4B, nozzles 472 and manifold 474are located on the same side of the planar substrate 454 as that where apressure cushion provided by nozzles 456 in communication with suitableapertures 452 is formed.

The levitated imaging system of FIG. 4B preferably also includes atleast one displacer 476 for moving the levitated planar substrate, alongand preferably parallel to table 450. The displacer 476 preferablycomprises a track 478 disposed parallel to the table 450. A carriageassembly 480 is driven along track 478 and preferably includes grippers482 which engage the planar substrate 454 and cause it to be displacedparallel to track 478. It is appreciated that alternatively, any othersuitable type of contact or non-contact displacer, such as a pusher orpuller, may be employed.

It is a particular feature of the embodiment of FIG. 4B that at leastsome of the nozzles 456 and 472 are coupled to an adaptive orificedevice which limits the fluid flow therethrough in the absence of alevitated planar surface in operative engagement therewith. The adaptiveorifice devices may be conveniently located in communication withapertures 452 in table 450. Preferred embodiments of adaptive orificedevices operative to provide a pressure cushion, or suction, withreduced flow of air are described in the following references, thedisclosures of which are hereby incorporated by reference in theirentirety:

-   -   Published PCT Patent Application WO 01/14782 A1    -   Published PCT Patent Application WO 01/14752 A1    -   Published PCT Patent Application WO 01/19572 A1.

It is appreciated that any other suitable adaptive or non-adaptiveorifice devices may be used.

Reference is now made to FIG. 5A, which is a simplified illustration ofa portion of a levitated two-sided imaging system constructed andoperative in accordance with a preferred embodiment of the presentinvention. The two-sided imaging system of FIG. 5A may be an imageacquisition system, such as one useful in inspection, or an imagewriting system or both. In the illustrated embodiment, an inspectionsystem is shown, it being understood that the general structuredescribed is applicable also to any other image acquisition system,image writing system, combined image acquisition and writing system, orsystem for processing substrates in which at least a portion of thesubstrate needs to be positioned a very precise distance from aprocessing station, and corresponding methodologies.

As seen in FIG. 5A, the levitated two-sided imaging system preferablyincludes a static levitation table 500 including a multiplicity ofapertures 502. A generally planar substrate 504 is levitated by apressure cushion, for example provided by a flow of fluid, preferablyair, from a multiplicity of nozzles 506, preferably in communicationwith corresponding apertures 502, that are connected via a manifold 508to a source of positive fluid pressure 510.

It is appreciated that absent the presence of a counter-flow of fluid,or other suitable hold down force, the levitated planar substrate may bebowed, or otherwise not uniformly flat, as shown in at referencenumerals 512 and 514. As shown in FIG. 5A, at an imaging location 516along the levitation table 500, there is provided a two-sided imagingdevice 518.

It is appreciated that the two-sided imaging device may comprise a pairof imaging devices or an integrated two-sided imaging device. Theimaging device which is disposed to image the underside of the planarsubstrate, i.e. the side facing the table 500, preferably views theplanar substrate through a gap or a transparent portion of the table 500which is not interfered with by the levitating and flatteningfunctionalities.

At the imaging location 516, it is desired that the planar substrate 504be flattened or otherwise maintained in a given precise orientationrelative to two-sided imaging device 518. Accordingly, there isprovided, in a preferred embodiment of the present invention, a counterflow of fluid, preferably air, forming a counter pressure cushionpreferably from a multiplicity of nozzles 522 connected via a manifold524 to the source of positive fluid pressure 510. In the embodiment ofFIG. 5A, nozzles 522 and manifold 524 are both located on an oppositeside of the planar substrate 504 from that where a pressure cushion isprovided by nozzles 506.

The levitated two-sided imaging system of FIG. 5A preferably alsoincludes a displacer 526 for moving the levitated planar substrate,along and preferably parallel to table 500. The displacer 526 preferablycomprises a track 528 disposed parallel to the table 500. A carriageassembly 530 is driven along track 528 and preferably includes grippers532 which engage the planar substrate 504 and cause it to be displacedparallel to track 528. It is appreciated that alternatively, any othersuitable type of contact or non-contact displacer, such as a pusher orpuller, may be employed. It is noted that when levitated, for example byan pressure cushion, substrate 504 can be readily laterally displaced,that displacer 526 does not need to support the full weight of planarsubstrate 504 and that displacer 526 only needs to provide a displacingfunctionality.

Reference is now made to FIG. 5B, which is a simplified illustration ofa levitated two-sided imaging system constructed and operative inaccordance with a preferred embodiment of the present invention. Thetwo-sided imaging system of FIG. 5B may be for example an imageacquisition system, such as one useful in inspection, or an imagewriting system or both. In the illustrated embodiment, an inspectionsystem is shown, it being understood that the structure described isapplicable also to any other image acquisition system, image writingsystem, combined image acquisition and writing system or any otherprocessing system requiring a substrate to be positioned a precisedistance from a processing station, and corresponding methodologies.

As seen in FIG. 5B, the levitated two-sided imaging system preferablyincludes a static levitation table 550 including a multiplicity ofapertures 552. A generally planar substrate 554 is levitated by apressure cushion, for example provided by a flow of fluid, preferablyair, from a multiplicity of nozzles 556, preferably in communicationwith corresponding apertures 552, that are connected via a manifold 558to a source of positive fluid pressure 560.

It is appreciated that absent the presence of a counter-flow of fluid,or other suitable hold down force, the levitated planar substrate 554may be bowed or otherwise not uniformly flat, as shown in at referencenumerals 562 and 564. As shown in FIG. 5B, at an imaging location 566along the levitation table 550, there is provided a two-sided imagingdevice 568.

It is appreciated that the two-sided imaging device may comprise a pairof imaging devices or an integrated two-sided imaging device, or anilluminator illuminating first side of planar substrate 554 and animager acquiring an image of light passing through the planar substrate554. The imaging device which is disposed to image the underside of theplanar substrate, i.e. the side facing the table 500, preferably viewsthe planar substrate through a gap or a transparent portion of the table550 which is not interfered with by the levitating and flatteningfunctionalities.

At the imaging location 566, it is desired that the planar substrate 554be flattened or otherwise maintained in a given orientation relative to,for example a precise distance from, two-sided imaging device 568.Accordingly, there is provided, in a preferred embodiment of the presentinvention, a counter flow of fluid. The counter flow may be simply afluid evacuator providing an outlet for evacuating air accumulatingbetween planar substrate 554 and static levitation table 550. Preferablycounter flow is a vacuum flow operative to hold at least a portion ofplanar substrate 554 in a plane that is located a precise distance fromthe surface of table 500, or any other suitable reference surface. Thecounter flow preferably is provided by a multiplicity of nozzles 572connected via a manifold 574 to a source of suction 576. In theembodiment of FIG. 5B, nozzles 572 and manifold 574 are located on thesame side of the planar substrate 554 as that where a pressure cushionprovided by nozzles 556 in communication with suitable apertures 552 isformed.

The levitated two-sided imaging system of FIG. 5B preferably alsoincludes a displacer 576 for moving the levitated planar substrate,along and preferably parallel to table 550. The displacer 576 preferablycomprises a track 578 disposed parallel to the table 550. A carriageassembly 580 is driven along track 578 and preferably includes grippers582 which engage the planar substrate 554 and cause it to be displacedparallel to track 578. It is appreciated that alternatively, any othersuitable type of contact or non-contact displacer, such as a pusher orpuller, may be employed.

It is a particular feature of the embodiment of FIG. 5B that at leastsome of the nozzles 556 and 572 are coupled to an adaptive orificedevice which limits the fluid flow therethrough in the absence of alevitated planar surface in operative engagement therewith. The adaptiveorifice devices may be conveniently located in communication withapertures 552 in table 550. Preferred embodiments of adaptive orificedevices operative to provide a pressure cushion, or suction, with areduced flow of air are described in the following references, thedisclosures of which are hereby incorporated by reference in theirentirety:

-   -   Published PCT Patent Application WO 01/14782 A1    -   Published PCT Patent Application WO 01/14752 A1    -   Published PCT Patent Application WO 01/19572 A1.

It is appreciated that any other suitable adaptive or non-adaptiveorifice devices may be used.

Reference is now made to FIG. 6, which is a simplified illustration ofinspection system, particularly useful for the inspection ofin-fabrication flat panel displays, constructed and operative inaccordance with a preferred embodiment of the present invention. As seenin FIG. 6, a static levitating table 600 is mounted on a chassis 602.Table 600 is preferably formed with a plurality of longitudinallyextending slits 604. Disposed in slits 604 are two sets of selectablyraisable rollers for receiving and conveying a generally planarsubstrate 606, such as an in-fabrication flat panel display or printedcircuit board.

The two sets of selectably raisable rollers preferably include an inputset 608, which receives and conveys a generally planar substrate 606 tobe inspected and an output set 610, which receives and conveys agenerally planar substrate 606 from an inspection station 612 afterinspection. It is appreciated that inspection station may include anysuitable optical inspection sensor, or other suitable device operativeto sense a desired physical attribute of generally planar substrate 606.

Disposed in slits 604 are a multiplicity of levitation nozzles 614 whichare operative to produce selectable levitation of generally planarsubstrates 606. Nozzles 614 preferably are coupled via a manifold (notshown) to a source of positive fluid pressure (not shown).

It is a particular feature of the embodiment of FIG. 6 that at leastsome of the nozzles 614 are coupled to an adaptive orifice device whichlimits the fluid flow therethrough, particularly in the absence of alevitated planar surface in operative engagement therewith. Preferredembodiments of adaptive orifice devices are described in the followingreferences, the disclosures of which are hereby incorporated byreference in their entirety:

-   -   Published PCT Patent Application WO 01/14782 A1    -   Published PCT Patent Application WO 01/14752 A1    -   Published PCT Patent Application WO 01/19572 A1.

At the inspection station 612, it is desired that the generally planarsubstrate 606 be flattened and held at a precise distance from thesurface of table 600 (or from imagers such as cameras 628) as it istransported therethrough. Accordingly, in addition to levitation nozzles614, there is provided, in a preferred embodiment of the presentinvention, a counter flow of fluid, preferably suction or a vacuum flow,preferably to a multiplicity of counter-force nozzles 616, connected viaa manifold (not shown) to a source of suction (not shown). In theembodiment of FIG. 6, counter-force nozzles 616 are located in thevicinity of inspection station 612 on the same side of planar electricalcircuit 606 as that impinged by the fluid flow from levitation nozzles614.

The inspection system of FIG. 6 also includes a displacer 620 for movingthe levitated generally planar substrates 606 along and preferablyparallel to table 600 when selectable raisable rollers are retractedinto slits 604. The displacer 620 preferably comprises a track 622disposed parallel to the table 600. A carriage assembly 624 is drivenalong track 622 and preferably includes grippers 626 which engage theplanar electrical circuits 606 and cause them to be displaced parallelto track 622. It is appreciated that alternatively, any other suitabletype of contact or non-contact displacer, such as a pusher or puller,may be employed. It is noted that when levitated, for example by anpressure cushion, substrate 606 can be readily laterally displaced, thatdisplacer 620 does not need to support the full weight of planarsubstrate 606 and that displacer 620 only needs to provide a displacingfunctionality.

Preferably, the inspection station 612 comprises a plurality of staticcameras 628, preferably mounted on a first bridge 630 spanning table600, and connected to an image processing computer (not shown).Inspection station 612 preferably also comprises a movable video camera632, preferably mounted on a second bridge 634, downstream of firstbridge 630, spanning table 600, and connected to a image post processingcomputer (not shown). A movable video camera 632 is preferably operativein response to inputs received from the image processing computer (notshown) for selectably viewing portions of the generally planar substrate606 which are suspected as being defective.

It will be appreciated by persons skilled in the art that the presentinvention is not limited by what has been particularly shown anddescribed hereinabove. Rather the scope of the present inventionincludes both combinations and subcombinations of the various featuresdescribed hereinabove as well as variations and modifications whichwould occur to persons skilled in the art upon reading the specificationand which are not in the prior art.

1-32. (canceled).
 33. A method for scanning generally planar substrates,comprising: conveying a generally planar substrate to be scanned with anair flow conveyor, to at least a scanning location, said planarsubstrate being selected from the group consisting of printed circuitboard, flat panel display and interconnect device substrates; flatteningsaid planar substrate with an air flow substrate flattener at least atsaid scanning location; and scanning said planar substrate with ascanner located at said scanning location, when flattened by said airflow substrate flattener, to acquire an image.
 34. A scanningmethodology according to claim 33 and wherein said air flow conveyorcomprises an air flow levitator.
 35. A scanning methodology according toclaim 33 and wherein said air flow conveyor comprises an air flow holddown.
 36. A scanning methodology according to claim 33 and wherein saidair flow substrate flattening functionality comprises a suction holddown.
 37. A scanning methodology according to claim 33 and wherein saidair flow substrate flattening functionality comprises an air cushionhold down.
 38. A scanning methodology according to claim 33 and whereinsaid conveying also comprises conveying said planar substrates away fromsaid imaging location.
 39. A scanning methodology according to claim 33and wherein said air flow conveyor includes a displacer for displacingsaid planar substrates at least towards said imaging location.
 40. Ascanning methodology according to claim 33 and wherein said air flowconveyor includes a displacer for displacing said planar substrates awayfrom said imaging location. 41 to
 82. (canceled).
 83. A flat bed scannersystem comprising: an air flow conveyor operative to convey printedcircuit board substrate to be scanned at least to a scanning location,said air flow conveyor having an air flow substrate flatteningfunctionality at least at said scanning location; and a scanner locatedat said scanning location for scanning said printed circuit boardsubstrate when flattened by said air flow substrate flatteningfunctionality.
 84. A flat bed scanner system according to claim 83 andwherein said scanner forms part of an image acquirer.
 85. A flat bedscanner system according to claim 83 and wherein said scanner forms partof an image creator.
 86. A flat bed scanner system according to claim 85and wherein said planar substrates include a photosensitive layer.
 87. Aflat bed scanner system according to claim 86 and wherein said imagecreator comprises a modulated laser beam device operative to expose adesired pattern on said photosensitive layer.
 88. A flat bed scannersystem according to claim 83 and wherein said air flow conveyorcomprises an air flow levitator.
 89. A flat bed scanner system accordingto claim 83 and wherein said air flow conveyor comprises an air flowhold down.
 90. A flat bed scanner system according to claim 83 andwherein said air flow substrate flattening functionality comprises anair cushion.
 91. A flat bed scanner system according to claim 83 andwherein said air flow substrate flattening functionality comprises asuction hold down.
 92. A flat bed scanner system according to claim 83and wherein said air flow conveyor is also operative to convey saidplanar substrates away from said imaging location.
 93. A flat bedscanner system according to claim 83 and wherein said air flow conveyorincludes a displacer for displacing said planar substrates at leasttowards said imaging location.
 94. A flat bed scanner system accordingto claim 83 and wherein said air flow conveyor includes a displacer fordisplacing said planar substrates away from said imaging location.95-110. (canceled).
 111. A method for scanning printed circuit boardsubstrates, comprising: conveying a printed circuit board substrate tobe scanned with an air flow conveyor, to at least a scanning location;flattening said printed circuit board substrate with an air flowsubstrate flattener at least at said scanning location; and scanningsaid planar substrate with a scanner located at said scanning location,when flattened by said air flow substrate flattener, to create an imageof a portion of an electrical circuit.
 112. A scanning methodologyaccording to claim 111 and wherein said air flow conveyor comprises anair flow levitator.
 113. A scanning methodology according to claim 111and wherein said air flow conveyor comprises an air flow hold down. 114.A scanning methodology according to claim 111 and wherein said air flowsubstrate flattening functionality comprises a suction hold down.
 115. Ascanning methodology according to claim 111 and wherein said air flowsubstrate flattening functionality comprises an air cushion hold down.116. A scanning methodology according to claim 111 and wherein saidconveying also comprises conveying said printed circuit board substrateaway from said imaging location.
 117. A scanning methodology accordingto claim 111 and wherein said air flow conveyor includes a displacer fordisplacing said printed circuit board substrate at least towards saidimaging location.
 118. A scanning methodology according to claim 111 andwherein said air flow conveyor includes a displacer for displacing saidprinted circuit board substrate away from said imaging location.119-138. (canceled).
 139. A flat bed scanner system comprising: an airflow conveyor operative to convey planar substrates to be scanned atleast to a scanning location, said air flow conveyor having an air flowsubstrate flattening functionality at least at said scanning location;and a scanner located at said scanning location for scanning said planarsubstrates when flattened by said air flow substrate flatteningfunctionality.
 140. A flat bed scanner system according to claim 139 andwherein said scanner forms part of an image acquirer.
 141. A flat bedscanner system according to claim 139 and wherein said scanner formspart of an image creator.
 142. A flat bed scanner system according toclaim 141 and wherein said planar substrates include a photosensitivelayer.
 143. A flat bed scanner system according to claim 142 and whereinsaid image creator comprises a modulated laser beam device operative toexpose a desired pattern on said photosensitive layer.
 144. A flat bedscanner system according to claim 139 and wherein said air flow conveyorcomprises an air flow levitator.
 145. A flat bed scanner systemaccording to claim 139 and wherein said air flow conveyor comprises anair flow hold down.
 146. A flat bed scanner system according to claim139 and wherein said air flow substrate flattening functionalitycomprises an air flow levitator.
 147. A flat bed scanner systemaccording to claim 139 and wherein said air flow substrate flatteningfunctionality comprises an air flow hold down.
 148. A flat bed scannersystem according to claim 139 and wherein said air flow conveyor is alsooperative to convey said planar substrates away from said imaginglocation.
 149. A flat bed scanner system according to claim 139 andwherein said air flow conveyor includes a displacer for displacing saidplanar substrates at least towards said imaging location.
 150. A flatbed scanner system according to claim 139 and wherein said air flowconveyor includes a displacer for displacing said planar substrates awayfrom said imaging location. 151-201. (canceled).